Specific interactions between proteins and nucleic acids are the fundamental events accompanying the expression, replication and packaging of genetic elements. This proposal describes studies of the molecular aspects of such interactions in the RNA-containing virus vesicular stomatitis virus, the DNA-containing viruses bovine papilloma virus as well as vaccinia and cowpox virus, and the plasmid pSC101. The approaches to these studies will include protein isolation and characterization, immunological analyses employing both standard antisera and monoclonal antibodies, nucleic acid sequencing, DNA cloning, the use of expression vectors and the alteration of specific DNA regions. More specifically, we propose to identify sequence-specific protein-nucleic acids interactions, sequence the nucleic acid regions involved in such interactions, alter such regions by introducing deletions, insertions, transpositions and oligonucleotide-directed mutations in order to identify the features that control such interactions, identify the proteins involved in such interactions by cloning their genes and expressing them in expression vectors, and studying the interactions themselves so as to determine how they regulate the three fundamental events referred to above.